Python Web Service with Basic Frontend and Backend (Flask)

Create a project structure for a simple Python web service using Flask with both backend and frontend components. The structure should include the following files, each with basic but functional content, so the service is ready to run locally on localhost:5000:

**app.py:**

A basic Flask app serving a homepage at /.

The app should render an index.html file using render_template.

**index.html:**

A simple HTML5 page with a welcoming message.

The page should be linked to an external style.css for basic styling and script.js for JavaScript functionality.

**style.css:**

Basic stylesheet for styling the index.html, including simple properties like centering content, padding, and colors.

**script.js**:

A basic JavaScript file for interactivity (e.g., a simple console.log message).

**requirements.txt:**

Contains Flask as the primary dependency so that the user can install it with pip.

**README.md:**

A beginner-friendly guide explaining how to run the app locally.

Instructions on installing dependencies (pip install -r requirements.txt), starting the Flask app (python app.py), and understanding the folder structure.

The app should be accessible at http://localhost:5000 once it's running.

The goal is to generate a minimal but functional and nicely styled project scaffold that users can extend into a real web service.